Department of Microbiology, School of Pathology of the University of the Witwatersrand, South African Institute for Medical Research, Johannesburg, Eye Department, Elim Hospital, Department of Ophthalmology, the University of the Witwatersrand, Northern Transvaal, South Africa
The prevalence of trachoma was studied in a representative sample of family units from a rural community. Evidence of current or previous infection was found in 82% of the total population, but there was a relatively low prevalence of intense upper tarsal disease. Most children acquire the disease within the first 3 yr of life, these primary infections having a tendency towards spontaneous cure without complications. The prevalence of active disease and potentially blinding sequelae is higher in elderly females than in males of the same age. Clinical and microbiological evidence suggests that trachoma is transmitted primarily within households in this community, the main source of infection appearing to be children of pre-school age. Chlamydiae were isolated from the eyes of children with intense upper tarsal disease, but not from elderly persons with similar clinical signs.